By Daniel Machin
Airlines will soon be given the first indication of how much they will be charged for using London's three main airports between 2014 and 2019 - something which will have an impact on air fares for passengers.
The Civil Aviation Authority (CAA) is due to provide initial proposals for Heathrow, Gatwick and Stansted airports on Tuesday.
It can cap the amount the airports can impose on airlines in take-off and landing fees, although a final decision will be made in January 2014.
Bosses at Heathrow want the aviation regulator to allow them to increase airline charges from the equivalent of £19.33 per passenger for 2012/13 to as much as £27.30 for 2018/19.
Gatwick chiefs, meanwhile, want to be free of CAA regulation altogether and have argued for a new seven-year, regulation-free regime. This would mean the per-passenger fee going up from £8.80 in 2014 to a maximum of £10.68 in 2020/21.
At Stansted, Ryanair chief executive Michael O'Leary has been particularly scathing of the CAA as a regulatory body. He has long railed against what he sees as excessive airline charges and vows to carry on doing so.
The announcement from the CAA will be the first time that a five-year set of charges has been declared when the three London airports have been under separate management.
Airport operator BAA - now known as Heathrow - used to run all three airports. However, Gatwick is now operated by Global Infrastructure Partners, while Stansted's new owner is the Manchester Airports Group.
In the 2014-19 regulations, the CAA now also has the power to alter licence conditions in the event of a number of factors.
For instance, the regulator could change an airport's licence if it performed poorly during bad weather one winter to ensure the problems did not happen again in the future.